> -----Original Message----- > From: platform-driver-x86-owner@xxxxxxxxxxxxxxx [mailto:platform-driver-x86- > owner@xxxxxxxxxxxxxxx] On Behalf Of Andy Shevchenko > Sent: Tuesday, November 28, 2017 1:28 PM > To: Alex Hung <alex.hung@xxxxxxxxxxxxx> > Cc: Jason Gerecke <killertofu@xxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; > Michal Kepien <kernel@xxxxxxxxxx> > Subject: Re: Intel "5-button array" support on MobileStudio Pro > > On Mon, Nov 27, 2017 at 3:42 PM, Alex Hung <alex.hung@xxxxxxxxxxxxx> wrote: > > On Sun, Nov 26, 2017 at 2:28 AM, Jason Gerecke <killertofu@xxxxxxxxx> wrote: > >> On November 25, 2017 10:23:33 AM PST, Jason Gerecke > <killertofu@xxxxxxxxx> wrote: > >>>I've just filed a bug [1] about a device which appears to use the > >>>"5-button array" that the patch [2] added support for earlier this > >>>year. It seems that on this particular device (a Wacom MobileStudio > >>>Pro), there is no "HEBC" entry in the ACPI table. Because of this, the > >>>kernel does not load support for the "5-button array" that this device > >>>seems to use. > > > > HEBC seems to be the control method that can report 5 button array; > > however, I think we can use either one of the below to workaround > > this: > > > > 1. Add a kernel parameter and a quirk (ex. DMI strings). The downside > > is the quirk can grow if more systems do not include HEBC > > > > 2. Check both HEBC & BTNL (ex. the method that enables 5 button > > array). Either one enables 5 button array and this fixes current > > problems. > > > > While 2 is preferable, nothing stops future BIOS skips BTNL in the future... > > > > Any comments? I will create a patch for testing in a few days. > > Looking for a tables with HEBC and this one I only can tell that I > would assume that tables w/o HEBC can guess HEBC returns value for > supporting 5-button array. > Though to be on the safe side I would rather vote for DMI based quirk Andy, Could you provide any insight how this possibly works on Windows? I would expect that corner cases like this should completely fall over on Windows since it's an Intel driver and not customized per OEM or anything. Maybe would it be possible for the folks at Intel who worked on the Windows driver to share information about anything different they're doing with regards to something like a possibly missing HEBC? It would be good to do the same rather than bandage on a bunch of things tied to DMI quirks. If it's not possible to obtain that information, then I would agree DMI quirks makes sense though. Thanks, > > > > >>>Please let me know what additional information would be helpful to > >>>provide. I am able to test kernel patches. > >>> > >>>[1]: https://bugzilla.kernel.org/show_bug.cgi?id=197991 > >>> > >>>[2]: https://patchwork.kernel.org/patch/9571353/ > > >>>Now instead of four in the eights place / > >>>you’ve got three, ‘Cause you added one / > >>>(That is to say, eight) to the two, / > >>>But you can’t take seven from three, / > >>>So you look at the sixty-fours.... > > > -- > With Best Regards, > Andy Shevchenko
